Bureaucrats, oversight, Administrators
1,823
edits
Changes
Jump to navigation
Jump to search
mLine 5:
Line 5: − + − + − + − + − + − + − + − <mm>[[Bacterias.mm|Flash]]</mm>+ Line 30:
Line 30: − 1. [https://en.wikipedia.org/wiki/Prokaryote]+ − 2.[https://en.wikipedia.org/wiki/Bacteria]+ − 1. NCERT Text Books.<br>+ + + + + + − − ===Concept Bacteria === + + Line 84:
Line 89: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Line 92:
Line 177: + + + + − Teacher can introduce the lesson on bacteria by giving a brief introduction about monera and prokaryotes.<br> ( Internal link the lesson Click here [[:File:1. introduction to monera.pdf]]Introduction to monera for reference). <br>+ + + + Line 119:
Line 211: − + − + Line 134:
Line 226: − Charts/ Diagrams + − Image credit-- Resources needed are Refer Link about images of habitat of bacteria in google search to show that bacteria is present everywhere. [http://www.google.co.in/#q=Images+of+habitat+of+bacteria]+ + + + + + + + + + + + + Line 147:
Line 251: − + + + + + + + + +
Text replacement - "</mm>" to ""
|-
|-
|style="width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
|style="width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
[http://www.karnatakaeducation.org.in/KOER/en/index.php/Science:_History The Story of Science]
[http://karnatakaeducation.org.in/KOER/en/index.php/Science:_History The Story of Science]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|[http://www.karnatakaeducation.org.in/KOER/en/index.php/Science:_Philosophy Philosophy of Science]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|[http://karnatakaeducation.org.in/KOER/en/index.php/Science:_Philosophy Philosophy of Science]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
[http://www.karnatakaeducation.org.in/KOER/en/index.php/Science:_Pedagogy Teaching of Science]
[http://karnatakaeducation.org.in/KOER/en/index.php/Science:_Pedagogy Teaching of Science]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
[http://www.karnatakaeducation.org.in/KOER/en/index.php/Science:_Curriculum_and_Syllabus Curriculum and Syllabus]
[http://karnatakaeducation.org.in/KOER/en/index.php/Science:_Curriculum_and_Syllabus Curriculum and Syllabus]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
[http://www.karnatakaeducation.org.in/KOER/en/index.php/Science:_Topics Topics in School Science]
[http://karnatakaeducation.org.in/KOER/en/index.php/Science:_Topics Topics in School Science]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
[http://www.karnatakaeducation.org.in/KOER/en/index.php/Textbooks#Science_-_Textbooks Textbooks]
[http://karnatakaeducation.org.in/KOER/en/index.php/Textbooks#Science_-_Textbooks Textbooks]
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
|style=" width:10%; border:none; border-radius:5px;box-shadow: 5px 5px 5px #888888; background:#f9f9ff; vertical-align:middle; text-align:center; "|
[http://www.karnatakaeducation.org.in/KOER/en/index.php/Science:_Question_Papers Question Bank]
[http://karnatakaeducation.org.in/KOER/en/index.php/Science:_Question_Papers Question Bank]
|}
|}
While creating a resource page, please click here for a resource creation [http://karnatakaeducation.org.in/KOER/en/index.php/Resource_Creation_Checklist '''checklist''']
While creating a resource page, please click here for a resource creation [http://karnatakaeducation.org.in/KOER/en/index.php/Resource_Creation_Checklist '''checklist''']
= Concept Map =
= Concept Map =
__FORCETOC__
__FORCETOC__
[[File:Bacteria.mm|Flash]]
= Textbook =
= Textbook =
==Useful websites==
==Useful websites==
3.1 Useful websites.:
3.1 Useful websites.:
#[https://en.wikipedia.org/wiki/Prokaryote Prokaryote]
#[https://en.wikipedia.org/wiki/Bacteria Bacteria]
==Reference Books==
==Reference Books==
#[http://ncert.nic.in/NCERTS/textbook/textbook.htm?hesc1=2-18 NCERT Text Book Chapter on Micro organism -Friend and foe]
2. PUC Ist year and 2nd Year Text Books.
2. PUC Ist year and 2nd Year Text Books.
==='''Concept Bacteria''' ===
==='''Metabolism in bacteria'''===
==='''Effects of Bacteria'''===
= Teaching Outlines =
= Teaching Outlines =
1. Habitat and size of Bacteria.<br>
1. Habitat and size of Bacteria.<br>
2. Classification of bacteria (based on shapes)<br>
2. Classification of bacteria (based on shapes)<br>
3. Structure of bacteria.<br>
3. Structure of bacteria.<br>
4.Metabolism in Bacteria( Nutrition and Reproduction)<br>
5. Effects of Bacteria
'''Episomes'''<br>
'''Episomes'''<br>
In addition to the DNA in some bacterial cells an additional circular DNA is present in the cytoplasm. It is called as episome or plasmid.<br>
In addition to the DNA in some bacterial cells an additional circular DNA is present in the cytoplasm. It is called as episome or plasmid.<br>
=====Metabolism in bacteria=====
4. '''Teaching outlines''':<br>
'''Metabolism-''' Some substances are broken down for energy for vital processes while others are synthesized for necessities of life. ,br.This is called Metabolism. It is a chemical process necessary for the maintenance of life. <br>
'''Nutrition'''
Nutrition is a process, in order for an organism to sustain life, to obtain food with life supporting substances that can be digested and used by the organism.
'''Mode of Nutrition''':<br>
Nutrition in bacteria are either '''autotrophs''' or '''heterotrophs'''.<br> Autotrophic bacteria are again divided into two groups;<br>
(i) '''Photoautorophs''' trap solar energy for utilization CO2 and use H2S in place of H2O. Thus, O2 is never released.<br>
(ii) '''Chemoautotrophs''' obtain energy from chemical by oxidation process for food synthesis and carbon from CO2.<br> This type include nitrifying bacteria, sulphur bacteria, iron bacteria etc.<br> Heterotrophs are also of two types- Photoheterotrophs and chemoheterotrophs. <br>Photoheterotrophs use light as energy source and an organic compound as source of carbon, e.g. Green and purple bacteria. <br>Chemoheterotrophs use chemical as energy and carbon may also be obtained from the same organic substances.<br> Most of the bacteria belong to this type.<br>
[[File:Mode of Nutrition in Bacteria.png|400px]]
'''Nutritional types in bacterial metabolism
'''
{|class="wikitable"
|-
|'''Nutritional type'''
|'''Source of energy'''
|'''Source of carbon'''
|'''Examples'''
|-
|Phototrophs
|Sunlight
|Organic compounds (photoheterotrophs) <br>or carbon fixation (photoautotrophs)
|Cynobacteria, Green sulphur Bacteria
|-
|Lithotrophs
|Inorganic Compounds
|Organic compounds (lithoheterotrophs) <br>or carbon fixation (lithoautotrophs)
|Thermodesulphobacteria,Nitrospirae
|-
|Organotrophs
|Organic Compounds
|Organic compounds (chemoheterotrophs) <br>or carbon fixation (chemoautotrophs)
|Bacillus,Clostridium
|-
|}
====Reproduction in Bacteria====
The sexual or asexual process by which organisms generate new individuals of the same kind is '''reproduction.'''<br>
'''Asexual Reproduction'''
Asexual is a form of where an animal can make its own offspring with no mate. Asexual is the primary form of reproduction.<br>
Asexual reproduction in bacteria is very simple. The cell increases in size. A double wall develops across the midline of the enlarged cell. <br>The cell separates into two cells at the midline wall. <br>Each cell is then able to function as a separate entity. The process of multiplication can be quite rapid.<br> The bacterium E. coli may double in number every 20 minutes in ideal conditions. If you plot the graph of population over time, you get an exponential increase.<br>
'''Sexual reproduction'''
Sex in bacteria differs somewhat from what we consider sex in eukaryotes. It involves the plasmid, which has several important characteristics:<br>
1. A plasmid is a loop of DNA. Plasmids can multiply autonomously within the cell. Thus we may find from zero to many of one or more plasmids in each cell.<br>
2. Many plasmids can insert into the DNA of the nucleus, and detach from it. In doing so, <br>the plasmid may leave part of the plasmid DNA behind, and take some of the nuclear DNA with it.<br>
3. plasmids can transfer from cell to cell. The cells need not be of the same bacterial 'species'.
====Effects of Bacteria====
'''Economic Importance( Useful effects)'''
Economic importance of any organism refers to the advantages and disadvantages of that organism to nature, the humans and the environment.<br> Bacteria, a prokaryote and microscopic organism, have the following economic importance:<br>
==Beneficial effects of Bacteria==
Bacteria play important roles in different fields such as agriculture, industry etc. Some of them are mentioned below: <br>
===Role in agriculture===
a) '''Scavenging Role''' Saprophytic bacteria obtain food from organic remains such as animal excreta, fallen leaves, meat etc. <br>They decompose these substances by action of digestive enzymes aerobically or anaerobically (known as fermentation). <br>Thus they help in sanitation of nature, so also known as scavengers. E.g. Pseudomonas <br>
b) ''' Nitrification''' Rhizobium bacteria, living in root nodules of leguminous plant symbiotically, helps in fixing atmospheric nitrogen. <br>Similarly, Nitrosomanas and Nitrococcus convert ammonium salt to nitrites.<br> Nitrites are further changed to nitrates by Nitrobacter and Nitrocystis. It enables plants to uptake nitrogen. <br>
c) '''Production of Organic Manure''' As stated above, saprophytic bacteria help in breaking of complex organic substance to simpler forms. <br>Thus, in this process, they help to convert farm refuse, dung and other wastes to manure. <br>
d) '''Preparation of Ensilage''' Ensilage is preserved cattle fodder prepared by packing fresh chopped fodder sprinkled with molasses. <br>Fermentation activity of bacteria produces lactic acid that acts as preservative in ensilage.<br>
e) '''Production of fuel''' Bacteria, while converting animal dung and other organic wastes to manure, help in production of fuel that is a must in gobar gas plant. <br>
f) ''' Disposal of sewage''' Bacteria help in disposal of sewage by decomposing it and thus, help in environmental sanitation.<br>
===Role in Industry===
a) '''Dairy Industry''' Bacteria such as Streptococcus lactis convert milk sugar lactose into lactic acid that coagulates casein (milk protein).<br> Then, milk is converted into curd, yoghurt, cheese etc needed for the industry. <br>
b) '''Production of Organic Compounds''' Fermentation (breakdown of carbohydrate in absence of oxygen) action of various bacteria produces organic<br> compounds like lactic acid (by Lactobacillus), acetic acid (by Acetobacter aceti), acetone (by Clostridium acetabutylicum) etc. <br>
c) '''Fibre Retting''' The action of some bacteria like Clostridium, Pseudomonas etc. help in fibre retting <br>i.e. separation of stem and leaf fibre of plants from other softer tissue.<br>
d) '''Curing''' The leaves of tea and tobacco, beans of coffee and coca are cured off their bitterness with the help of action of certain bacteria such as Bacillus megatherium. <br>
e) '''Production of Antibiotics''' Number of anti bacterial and anti fungal antibiotics such as Hamycin, Polymyxin, Trichomycin etc are obtained from <br>mycelia bacteria (like Streptomyces). Similarly, Bacillus is used for production of antibiotics such as Bacitracin, Gramicidin etc <br>
f) '''Production of Vitamins''' Different kinds of vitamins are produced from bacteria like Riboflavin from Clostridium butylicum, Vitamin B12 from Bacillus megatherium and Vitamin K and B-complex from Escherichia coli. <br>
==Harmful effects of Bacteria==
Though bacteria plays important role in agriculture, industries and natural sanitation etc, it has the following harmful effects: <br>
a) '''Food Spoiling''' Saprophytic bacteria always not only help in decomposition of dead matters, but they also cause the rotting of vegetables, <br>fruits, meat, bread etc. <br>
b) '''Food Poisoning''' Bacteria like Staphylococcus aureus cause food poisoning and cause people diarrhea and vomiting.<br>
c) '''Damaging of domestic articles''' Spirochete cytophaga deteriorates cotton, leather and wooden articles.<br>
d) '''Denitrification''' Bacteria such as Thiobacillus and Microbacillusconvert nitrate of the soil to the gaseous nitrogen. This hampers plants very much.<br>
e) ''' Desulphurication''' Bacteria such as Desulfovibrio convert soil sulphates into hydrogen sulphide. <br>
f) '''Cause of Diseases''' It is known that over 90% of human diseases and over 10% of plant diseases are caused by bacteria.<br>
===Learning objectives===
===Learning objectives===
#Classify bacteria on the basis of shapes.
#Classify bacteria on the basis of shapes.
#Identify the structure and morphology of bacteria.
#Identify the structure and morphology of bacteria.
#understand the modes of nutrition in bacteria.
#Identify differences between the asexual and sexual types of reproduction in bacteria.
#understand the economic importance of bacteria and its uses.
#describe about the harmful effects of bacteria.
===Notes for teachers===
===Notes for teachers===
Teacher can introduce the lesson on bacteria by giving a brief introduction about monera and prokaryotes.<br> ( Internal link the lesson Click here [[:File:1. introduction to monera.pdf]]<br>
Introduction to monera for reference).<br>
Refer this link to show bacteria on Human Body and its effects.[http://t2.gstatic.com/images?q=tbn:ANd9GcSdG85L1SRf5DY-ptAg3VrowS8dwS2Cq4iAXG9p9Wy4NltDqUtc2g]<br>
'''It is better if teachers refer the websites concerned to the topic . Few links are given in web resources heading.'''<br>
4. Teacher Should be familiar with the meaning of following terms related to bacteria.<br>
4. Teacher Should be familiar with the meaning of following terms related to bacteria.<br>
'''Words to Know''' <br>
'''Words to Know''' <br>
*Demonstrating the below experiment of milk changing into curds and by showing the figure about bacterial infection on man.
*Demonstrating the below experiment of milk changing into curds and by showing the figure about bacterial infection on man.
Thus students can get clear idea that bacteria are found everywhere.<br>[[File:Bacteria.jpg|100px]][[File:Bacteria on key board.jpg|100px]]
Thus students can get clear idea that bacteria are found everywhere.<br>[[File:Bacteria.jpg|100px]] [[File:Bacteria on key board.jpg|200px]]
===Activity No 1 ===
===Activity No 1 ===
{| style="height:10px; float:right; align:center;"
{| style="height:10px; float:right; align:center;"
|<div style="width:150px;border:none; border-radius:10px;box-shadow: 5px 5px 5px #888888; background:#f5f5f5; vertical-align:top; text-align:center; padding:5px;">
|<div style="width:150px;border:none; border-radius:10px;box-shadow: 5px 5px 5px #888888; background:#f5f5f5; vertical-align:top; text-align:center; padding:5px;">
''[http://www.karnatakaeducation.org.in/?q=node/305 Click to Comment]''</div>
''[http://karnatakaeducation.org.in/?q=node/305 Click to Comment]''</div>
|}
|}
*
*
Time Required: 20 Minutes.<br>
Time Required: 20 Minutes.<br>
*Multimedia resources<br>
*Multimedia resources<br>
Charts/ Diagrams
*'''Website interactives/ links/ simulations'''<br>
*'''Website interactives/ links/ simulations'''<br>
Wesite interactions/links/ simulations
Wesite interactions/links/ simulations
Image credit-- Resources needed are Refer Link about images of habitat of bacteria in google search
#[http://www.google.co.in/#q=Images+of+habitat+of+bacteria Habitat of Bacteria] <br>
#Ppt. on structure of Bacteria [[:File:Bacterial Structures (1).pdf]]
#[http://www.scribd.com/doc/6694153/Lecture-4-Bacteria-Nutrition-Metabolism-and-Growth Nutrition]
#[http://bugs.bio.usyd.edu.au/learning/resources/CAL/Microconcepts/moviePages/conjugation.html Animation of Sexual Reproduction in Bacteria]
#[http://bugs.bio.usyd.edu.au/learning/resources/CAL/Microconcepts/moviePages/Ecoli.html Reproduction in E.Coli.]
#[http://bugs.bio.usyd.edu.au/learning/resources/CAL/Microconcepts/moviePages/bacteriaDivision.html Bacteria Reproduction]
#[http://pdfsdb.com/ppt/economic-importance-of-bacteria-ppt Economic importance of Bacteria]
# Additional Information[http://www.scienceclarified.com/As-Bi/Bacteria.html#ixzz2WGcoDtB2 to know about bacteria]
#[http://www.scienceclarified.com/As-Bi/Bacteria.html#ixzz2WGcoDtB2 Effects of Bacteria]
#[http://truth-out.org/opinion/item/25241-all-the-blood-in-your-body A very scary article on the spread of the ebola virus in Africa in July 2014]
Refer this link to show ppt on various topics in Science [http://www.worldofteaching.com/sciencepowerpoints.html]
*'''Process/ Developmental Questions'''<br>
*'''Process/ Developmental Questions'''<br>
2. Draw the different shapes of bacteria on drawing sheet , name them and display in class room.<br>
2. Draw the different shapes of bacteria on drawing sheet , name them and display in class room.<br>
3. Why does the milk get spoilt during summer? Does it get spoilt if we boil milk? If not, why?<br>
3. Why does the milk get spoilt during summer? Does it get spoilt if we boil milk? If not, why?<br>
4. Similarly which food items get spoilt soon? Why?
4. Similarly which food items get spoilt soon? Why?<br>
'''Questions corner'''.After going through the images and seeing the picture, what can we conclude about habitat of bacteria?<br> Are they found even on your body?!
= Project Ideas =
= Project Ideas =
'''Do this activity at home''': About a cup of milk is taken in a vessel & kept for 1-2days. Similarly A lemon is cut into halves and kept for 2days.<br> After 2 days students will observe the changes and give the reasons for the change.)<br>
'''Evaluation Activity: CCE'''
#Visit nearby hospital and Collect information of common harmful diseases caused by bacteria.<br>
#Collect information and pictures about various uses of fermentation(in preparation of food , gober gas etc)<br>
Refer this link . Print the worksheets for Evaluation.[http://www.yourfilezone.com/signup?sf=search_books&ref=4947201&q=worksheets+bacteria+pdf Worksheet for Bacteria]<br>
Refer this picture and prepare notes on harmful bacteria, their effects on human body[http://t2.gstatic.com/images?q=tbn:ANd9GcSdG85L1SRf5DY-ptAg3VrowS8dwS2Cq4iAXG9p9Wy4NltDqUtc2g]
= Fun corner =
= Fun corner =